Over time, various approaches have been employed to achieve ever higher processing performance in computer systems, including both operating processor cores at ever greater frequencies, and increasing the number of processor cores operating in parallel within the same computer system. However, both approaches suffer the disadvantages of increasing both the amount of power consumed and heat dissipated during the operation of such computer systems. More precisely, as the operating frequency of a processor core is increased, the amount of power required for the operation of that processor core increases and the amount of heat dissipated by that same processor core also increases. Also, as the number of processor cores operating within a given computer system increases, regardless of whether all the cores are fabricated on a single die or not, there is again, an increase in both the amount of power required and the amount of heat that is dissipated.
Finding ways to accommodate the ever greater quantities of heat dissipated has repeatedly proven to be quite problematic, regardless of whether the greater quantity of heat dissipated is due to a processor core operating at a higher frequency or is due to an increased number of processor cores being operated in parallel. Preventing damage to components within a computer system from the dissipation of increased quantities of heat often requires additional hardware such as more or larger fans, more or larger heatsinks, heatsinks with integrated heatpipes, heat exchangers with heatpipes, cooling systems based on liquid coolant, etc. Another, but related problem can be limits on the ability of the processor cores, themselves, to dissipate additional heat without damage. Such limits may arise from the packaging used to contain and protect the die on which one or more processor cores have been etched, or may arise from thermal limitations of the die, itself.
Limitations on the ability of processor cores to dissipate additional heat without damage become more acute as processor cores are designed with ever greater numbers of transistors in ever tighter spaces and as the practice of placing more than one processor core on the same die become more commonplace. As a result, schemes have been devised to manage the total heat dissipation of a given die equipped with multiple cores by placing a limit on the number of cores that may be allowed to be active at any one time, such that at least one of the cores is always in an inactive state. However, a significant drawback to this is that, invariably, as a result of an inflexible limit on the number of active cores at any one time, a core serving a time-critical software process is inevitably shut down for a long enough period of time as to cause irreparable disruptions to that software process. In an effort to resolve this concern, an approach of requiring a rotation of which processor cores are shut down such that no one core remains shut down for longer than a predetermined period of time has been considered. However, as long as one or more processor cores are required to be shut down, there continues to be a risk that a software process will eventually be starved to the point of failure by being forced to remain completely inactive for too long.